How can I de-select/ Unfocus everything when presing ESC - javafx

Question

I have the following mini-app:
public class TestApp extends Application {
public static void main(final String[] args) {
launch(args);
}
private final AtomicLong counter = new AtomicLong();
#Override
public void start(final Stage primaryStage) {
final VBox root = new VBox(5);
root.setPadding(new Insets(10));
root.setAlignment(Pos.CENTER);
final TableView<String> tableView = new TableView<>();
final TableColumn<String, String> column = new TableColumn<>("Text");
column.setCellValueFactory(f -> new SimpleStringProperty(f.getValue()));
tableView.getColumns().add(column);
// Add some sample items to our TableView
for (int i = 0; i < 100; i++) {
tableView.getItems().add("Item #" + counter.incrementAndGet());
}
final Button button = new Button("Add items");
final TextArea t1 = new TextArea();
button.setOnAction(e -> {
final long oldElement = counter.get();
// Add more elements
for (int i = 0; i < 10; i++) {
tableView.getItems().add("Item #" + counter.incrementAndGet());
}
tableView.scrollTo("Item #" + oldElement);
});
root.getChildren().add(button);
root.getChildren().add(t1);
root.getChildren().add(tableView);
// Show the Stage
primaryStage.setWidth(300);
primaryStage.setHeight(300);
primaryStage.setScene(new Scene(root));
primaryStage.show();
}
}
When it starts up, the button has focus. If I click in the TextArea, it gets focus.
There is no way now to "unfocus" the TextArea again, besides pressing the button (which will trigger an action, which is unwanted if I only want to get rid of the focus).
How can I release all focus and deselect everything, for example when I pres ESC?

Answer 1

I don't know if this fully meets your requirements, but you can create a boolean variable to keep up with the state of ESCAPE. You can also use a ChangeListener that allows the root node to regain focus anytime it loses it.
import java.util.concurrent.atomic.AtomicLong;
import javafx.application.Application;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.TextArea;
import javafx.scene.input.KeyCode;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
public class TestApp extends Application
{
boolean escActive = false;
final VBox root = new VBox(5);
ChangeListener<Boolean> changeListener1 = new ChangeListener()
{
#Override
public void changed(ObservableValue observable, Object oldValue, Object newValue)
{
System.out.println(newValue);
root.requestFocus();
}
};
public static void main(final String[] args)
{
launch(args);
}
private final AtomicLong counter = new AtomicLong();
#Override
public void start(final Stage primaryStage)
{
root.setPadding(new Insets(10));
root.setAlignment(Pos.CENTER);
final TableView<String> tableView = new TableView<>();
final TableColumn<String, String> column = new TableColumn<>("Text");
column.setCellValueFactory(f -> new SimpleStringProperty(f.getValue()));
tableView.getColumns().add(column);
// Add some sample items to our TableView
for (int i = 0; i < 100; i++) {
tableView.getItems().add("Item #" + counter.incrementAndGet());
}
final Button button = new Button("Add items");
final TextArea t1 = new TextArea();
button.setOnAction(e -> {
if (!escActive) {
final long oldElement = counter.get();
// Add more elements
for (int i = 0; i < 10; i++) {
tableView.getItems().add("Item #" + counter.incrementAndGet());
}
tableView.scrollTo("Item #" + oldElement);
}
});
root.getChildren().add(button);
root.getChildren().add(t1);
root.getChildren().add(tableView);
root.setOnKeyReleased((event) -> {
System.out.println(event.getCode());
if (event.getCode() == KeyCode.ESCAPE) {
escActive = !escActive;
if (escActive) {
root.requestFocus();
root.focusedProperty().addListener(changeListener1);
}
else {
root.focusedProperty().removeListener(changeListener1);
}
}
});
// Show the Stage
primaryStage.setWidth(300);
primaryStage.setHeight(300);
primaryStage.setScene(new Scene(root));
primaryStage.show();
}
}